Successful Aging

This issue's Works in Progress department presents six abstracts for projects that are developing interesting solutions to the elderly's quality of life challenges. The first two abstracts discuss projects that will help provide the elderly with freedom and independence by instrumenting their environments with supportive technology. The next two abstracts discuss projects building specialized user interfaces for addressing some of the challenges associated with aging, such as vision impairment. The final two abstracts present projects that will aid independence for the elderly by providing remote monitoring and assistance.     

Constructing a short form of the Smoking Consequences Questionnaire with adolescents and young adults.

The goal of the present studies was to construct and validate a short form of the 50-item Smoking Consequences Questionnaire (SCQ; T. H. Brandon & T. B. Baker, 1991), a measure of smoking outcome expectancies. In Study 1, a 21-item short form (S-SCQ) was derived from a sample of 107 young adults previously treated for substance abuse. In Study 2, the measure was cross-validated on 125 adolescents in treatment for substance abuse. Confirmatory factor analyses revealed good model fit and factorial invariance for the 4 S-SCQ subscales across both samples. Validation analyses on each sample found that subscale scores generally correlated significantly with smoking-related variables. The present studies provide initial evidence for the utility of the S-SCQ when used with young adults and adolescents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Plateletapheresis with a next generation blood cell separator

Baeyer-Villiger monooxygenases (BVMOs) are enzymes able to perform highly regio-plus steroselective nucleophilic and electrophilic biooxygenations on various substrates. The resultant chiral products (lactones and sulfoxides) can be valuable for the chemoenzymatic synthesis of a wide range of useful compounds. Recent studies have provided a number of alternative active-site models that attempt to explain the exquisite and unusual selectivity of BVMOs. This article reviews some of the established applications, and considers the merits of the various predictive models.     

The history of wireless power transmission

The history of wireless power transmission at microwave frequencies is reviewed with emphasis upon the time period starting with the post World War II efforts to use the new microwave technology developed during the war. A nationally televised demonstration of a microwave powered helicopter at the Spencer Laboratory of the Raytheon Co., in 1964 was the result of these early efforts and broadly introduced the concept of wireless power transmission to scientific and engineering communities and to the public. Subsequent development efforts centered on improving the efficiency of the interconversion of d.c. and microwave power at the ends of the system to reach a demonstrated overall d.c. to d.c. system efficiency of 54% in 1974. The response to the requirements of applications such as the Solar Power Satellite and high altitude microwave powered aircraft have changed the direction of technology development and greatly expanded the technology base. Recent and current efforts are centered on examining the use of higher frequencies than the baseline 2.45 GHz, and in reducing the system costs at 2.45 GHz.     

Implementing Information Systems: Some Practical Advice and a Richer Model

Recent research suggests that implementing information systems presents considerable difficulties and that many implementations are total or partial failures. This paper argues that what both practitioners and students require are richer and more acceptable models of information systems implementation. Accordingly, case study data concerning the introduction of manufacturing resource planning (MRP II) are used to illustrate five patterns of behaviour (rites) which capture important social actions; and four components of changing psychological orientation. It is argued that appreciation of the rites and psychological developments identified here will support effective change programmes. Guidelines based on our model are provided for practitioners.     

Modern electronic and chemical thermometers used in the axilla are inaccurate

Rectal and axillary temperatures were measured simultaneously in 83 children using three different thermometer devices providing 166 pairs of results. In the first series consisting of 22 febrile children (44 measurements) and 20 afebrile children (40 measurements), the rectal mercury measurement was compared to an axillary mercury and axillary Tempa-DOT thermometer. The axillary mercury had sensitivity of 14/22 (64%) and specificity of 20/20 (100%) while the Tempa-DOT had sensitivity of 15/22 (68%) and specificity of 19/20 (95%). In the second series comprising 21 febrile children (42 measurements) and 20 afebrile children (40 measurements) the axillary mercury had sensitivity of 11/21 (52%) and specificity of 20/20 (100%) while the electronic thermometer had sensitivity of 10/21 (48%) and specificity of 20/20 (100%). Regardless of the thermometer used, the axilla is a poor alternative to rectal measurements in the diagnosis of fever. CONCLUSION: Mercury-free thermometers, when used in the axilla are as poor alternatives to rectal measurements as mercury-in-glass thermometers.     

Structure of very early protein folding intermediates: new insights through a variant of hydrogen exchange labelling

BACKGROUND: Hydrogen exchange labelling has been a key method in characterizing the structure of transient folding intermediates. In studies of several proteins, however, there has been clear spectroscopic evidence for partial folding of some kind at very early times, before any protection from exchange was measurable. These results, presumably a consequence of limited stability of specific backbone interactions, have made it difficult to assess the extent of native-like folding in the very early intermediates. We have used a variant of the labelling method to investigate marginally stable structures formed within the first few milliseconds of refolding of two such proteins, hen lysozyme and ubiquitin. RESULTS: In lysozyme, population of a subset of native-like secondary structures on this timescale is revealed, thus reconciling the exchange behaviour with circular dichroism measurements and confirming the significance of the rapidly formed embryonic structure as a foundation for the subsequent folding pathway. In the case of ubiquitin, by contrast, no significantly protective structure was detectable, suggesting that here secondary structural elements can be populated only marginally ahead of the major cooperative folding event; this was also supported by stopped-flow circular dichroism measurements. CONCLUSIONS: The hydrogen exchange approach can be extended to probe the formation of native-like structure formed in very early folding intermediates, even when the stability of specific interactions is marginal. In the case of lysozyme, this has provided a new window on an early stage of organization of the alpha-helical domain.     

Crystal structures of Escherichia coli and Salmonella typhimurium 3-isopropylmalate dehydrogenase and comparison with their thermophilic counterpart from Thermus thermophilus

The basis of protein stability has been investigated by the structural comparison of themophilic enzymes with their mesophilic counterparts. A number of characteristics have been found that can contribute to the stabilization of thermophilic proteins, but no one is uniquely capable of imparting thermostability. The crystal structure of 3-isopropylmalate dehydrogenase (IPMDH) from the mesophiles Escherichia coli and Salmonella typhimurium have been determined by the method of molecular replacement using the known structure of the homologous Thermus thermophilus enzyme. The structure of the E. coli enzyme was refined at a resolution of 2.1 A to an R-factor of 17.3%, that of the S. typhimurium enzyme at 1.7 A resolution to an R-factor of 19.8%. The three structures were compared to elucidate the basis of the higher thermostability of the T. thermophilus enzyme. A mutant that created a cavity in the hydrophobic core of the thermophilic enzyme was designed to investigate the importance of packing density for thermostability. The structure of this mutant was analyzed. The main stabilizing features in the thermophilic enzyme are an increased number of salt bridges, additional hydrogen bonds, a proportionately larger and more hydrophobic subunit interface, shortened N and C termini and a larger number of proline residues. The mutation in the hydrophobic core of T. thermophilus IPMDH resulted in a cavity of 32 A3, but no significant effect on the activity and thermostability of the mutant was observed.